Along an assembly line, various types of articles, such as for example, diapers and other absorbent articles, may be assembled by adding components to and/or otherwise modifying an advancing, continuous web of material. For example, in some processes, advancing webs of material are combined with other advancing webs of material. In other examples, individual components created from advancing webs of material are combined with advancing webs of material, which in turn, are then combined with other advancing webs of material. In some cases, individual components created from an advancing web or webs are combined with other individual components created from other advancing webs. Webs of material and component parts used to manufacture diapers may include: backsheets, topsheets, leg cuffs, waist bands, absorbent core components, front and/or back ears, fastening components, and various types of elastic webs and parts such as leg elastics, barrier leg cuff elastics, stretch side panels, and waist elastics. Once the desired component parts are assembled, the advancing web(s) and component parts are subjected to a final knife cut to separate the web(s) into discrete diapers or other absorbent articles.
Some absorbent articles have components that include elastic parts, such as for example, elastic laminates. Such elastic laminates may include an elastic material bonded to one or more substrates, such as nonwovens. The elastic material may include an elastic film and/or elastic strands. In some elastic laminates, a plurality of elastic strands are joined to a nonwoven while the plurality of strands are in a stretched condition so that when the elastic strands relax, the nonwoven gathers between the locations where the nonwoven is bonded to the elastic strands forming corrugations. The resulting elastic laminate is stretchable to the extent that the corrugations allow the elastic strands to elongate.
When manufacturing absorbent articles, a continuous elastic laminate may be assembled in a stretched condition. The continuous elastic laminate may be subsequently cut into discrete lengths and subsequently combined with other absorbent article components while maintaining the stretched condition of the discrete elastic laminates. In some assembly configurations, elastic laminates may initially advance in a machine direction through the converting process in a stretched condition wherein the direction of stretch is parallel with the machine direction. The elastic laminates may then be transferred to device, such as a rotating drum, that reorients the elastic laminates by 90 degrees such that the direction of stretch is perpendicular to the machine direction. In a subsequent assembly operation, the reoriented elastic laminate may be combined with another advancing substrate and/or component while maintaining the elastic laminate in a stretched condition.
However, problems can be encountered during the manufacture of absorbent articles with elastic laminates that may be associated with reorientation and/or combining operations while maintaining the elastic laminate in a stretched condition. For example, during a reorientation process, such as mentioned above, elastic laminates may be held in a stretched state on an outer surface of a drum with vacuum pressure. As such, the outer surface of the drum may include apertures in fluid communication with a vacuum source. In some configurations, vacuum pressure may cause portions of the elastic laminate to be partially pushed into the apertures in order to help hold the length elastic laminate on the outer surface a fixed position and prevent undesired contraction. Although having portions of the elastic laminate held in position by the apertures may help to maintain the stretched condition of the elastic laminate, this may cause problems with subsequent assembly operations. For example, portions of the elastic laminate may become stuck or snagged on the aperture edges while attempting to transfer the reoriented elastic laminate from the drum to be combined with another substrate. In some instances, steps may be taken to help mitigate problems associated with stuck or snagged laminates during transfer operations, such as chamfering aperture edges or reducing the vacuum pressure. However, such mitigating steps may adversely affect the ability of the rotating drum to hold the elastic laminate in the desired stretched condition.
Consequently, it would be beneficial to provide a method and apparatus for assembling absorbent articles that helps to maintain an elastic part in a stretched condition as an elastic part is reoriented relative to a machine direction, while at the same time helping to reduce problems associated with sticking and/or snagging of the reoriented elastic part during subsequent transfer and/or assembly operations.